土石流の2層モデルに関する実験的検証

Abstract

There remain much uncertainties in fundamental hydrodynamics of debris flows, because it is very hard to measure velocity profiles and related turbulence structure. Debris flows could be classified corresponding to the bottom slope. In the mild slop situation, it is similar to open-channel flow with bed-load transport. Whereas in the steep slope, debris flow occurs, in which high concentration sediments are rolled up to the free-surface. Between them, we can see a two-layer current composed of an upper clearwater layer and a lower highly-concentrated sediment layer. The present study focuses on this two-layer debris flows and examine previous theory of velocity profile comparing with measured data in a short-fetch narrow flume.